Eri Nara, a high school girl meets a mysterious transfer student. On that day, they both encountered a flesh eating creature, as Eri sacrificed her life to save the new guy from his death. Little did she know that the person she desperately tried to save is none other than the Prince of the Underworld, known as William Idle Westman. He brings Eri back to life in exchange for loyalty as a member of the Westman Clan. Find out how Eri meets the rest of the clan.